Distal vs Conventional Radial Access for Coronary Angiography and/or Intervention: A Meta-Analysis of Randomized Trials

Distal Transradial Access Optimization: A Prospective Trial of Ultrasound-Guided Radial Artery Characterization for the Anatomical Snuffbox

Background/Objectives: The distal transradial approach (dTRA) is increasingly used in interventional cardiology. Doppler Ultrasound (DUS) effectively assesses radial artery (RA) characteristics. This study aims to identify specific RA DUS characteristics in patients undergoing coronary procedures via dTRA. Methods: Participants from the ANTARES trial who completed the intervention per-protocol and retained RA patency were included. DUS was performed at baseline, 1 day, and 60 days post-procedure. Results: Among 400 participants, 348 had either dTRA (n = 169) or conventional transradial access (cTRA) (n = 179). Distal RA lumen diameter was 12% smaller than that of the proximal RA (p < 0.001). Men had a 14% larger distal RA diameter than women (2.33 ± 0.31 mm vs. 2.04 ± 0.27 mm, p < 0.0001), similar to the proximal RA relationship. Peak flow velocities were similar between the sexes. Univariate linear regression showed that height, weight, body mass index, and body surface area (BSA) predicted arterial size, with BSA remaining significant in multivariate analysis (beta coefficient 0.62; confidence interval 0.49-0.75; p < 0.0001). Distal RA diameter correlated positively with palpable pulse at the snuffbox and wrist. The dTRA resulted in an immediate 14% and 11% increase in distal and proximal RA diameter, respectively (both p < 0.05). Sixty days after dTRA, the distal RA remained slightly dilated (p < 0.05), while the proximal RA returned to baseline. Conclusions: Distal RA diameter is significantly associated with sex, measuring smaller than the forearm segment. A strong palpable pulse correlates with larger distal RA size. The dTRA induces RA lumen expansion. A thorough understanding of distal RA anatomy is essential for optimizing patient selection and refining techniques for transradial procedures.

Feasibility and safety of left distal trans-radial approach for coronary angiogram and percutaneous coronary intervention in a center in Hong Kong

INTRODUCTION

The left distal trans-radial approach is not only more convenient for the operator than the conventional left forearm radial approach, it is also more comfortable for right-hand patients during the peri-procedural period. Comparing with conventional approach, it has lower bleeding risk, less pain and lower risk of radial artery occlusion. The aim of this study was to determine the feasibility and the safety of left distal trans-radial approach for coronary angiogram and percutaneous coronary intervention in Hong Kong Chinese who had smaller body built and therefore smaller radial arterial size.

METHOD

In this single-center prospective study, 72 patients undergoing elective coronary angiography and/or percutaneous coronary intervention were recruited from August to October 2018. All right-handed patients aged 18 or above undergoing elective procedures during the period were recruited. Exclusion criteria were non-palpable radial arteries, pregnancies, incapability to consent, abnormal Allen's test, and emergency procedures. Sixty patients (42 males, age ranging from 45 to 86 years old) were recruited and underwent the procedures via left distal radial approach. The measurements during access establishment, the procedure details, complications, patients' satisfaction, and arterial occlusion rate were studied.

RESULTS

The procedures with left distal radial approach were successful in 51 patients (85%). Crossover rate to conventional right radial approach was 15% (nine patients). Among successful cases, the mean patients' satisfaction was 8.32/10 and the mean pain score was 1.6/10. Post-procedural radial artery occlusion was not encountered.

CONCLUSION

Left distal radial approach is a feasible alternative for patients undergoing coronary angiography and/or percutaneous coronary intervention in Hong Kong Chinese patients. It provides good comfortability with minimal pain in right-handed patients. The risk of radial artery occlusion is minimal.

Ultrasound-guided modified dynamic needle tip positioning technique for distal radial artery catheterization: A randomized controlled trial

INTRODUCTION

The distal radial artery presents a particular challenge for puncture and catheterization due to its diminutive size, tortuous path, and tendency to spasm, increasing the risk of procedural failure and injury. Ultrasound guidance improves success rates and reduces risk in radial artery catheterization. This study evaluates the efficacy and safety of a refined dynamic needle tip positioning technique for distal radial artery access.

METHODS

One hundred twelve patients were randomized to either the modified dynamic needle tip positioning technique (MDNTP) or palpation guidance groups (palpation group), each with 56 participants. The primary outcomes were the success rate of the initial puncture and overall puncture success rate, while secondary outcomes included procedural time and complications such as puncture site hematoma and radial artery occlusion within 24 h.

RESULTS

The MDNTP group exhibited superior initial puncture success (71.43% vs 46.43%, p < 0.05) and fewer puncture attempts (median 1 (1, 2) vs 2 (1, 4), p < 0.05), resulting in a higher overall puncture success rate (98.21% vs 87.50%, p = 0.028). Notably, sheath insertion times were significantly shorter (17 (12, 21) s vs 57 (32, 100) s, p = 0.001) and the Sheath insertion success rate was higher (96.43% vs 82.14%, p = 0.015) in the MDNTP group. Furthermore, the incidence of puncture site hematomas was reduced (5.36% vs 19.64%, p = 0.022), although puncture time was longer (60 (28, 116) s vs 40 (15, 79) s, p = 0.033). Despite these differences, total procedural time and the incidence of radial artery occlusion at 24 h postoperatively were comparable between the two groups.

CONCLUSION

The MDNTP technique boosts the success of distal radial artery puncture and catheterization, reducing the risk of complications associated with the procedure.

Is catheterization via distal transradial access feasible in children? From vessel diameter perspective

Background

Distal radial artery (DRA) access is an infrequent alternative access for pediatric catheterization. The feasibility of using the DRA for arterial catheterization in children depends on the vessel's size.

Objectives

This study aims to provide a reference for pediatric catheterization via DRA access by evaluating the diameter of the DRA in the anatomic snuffbox (AS).

Methods

We conducted a retrospective review of clinical and vascular ultrasound data of 412 children (ages 3-12) who were scheduled for arterial blood gas analysis via the DRA due to serious respiratory diseases between June 2023 and October 2023.

Results

The corrected DRA diameter in the AS was 1.97 ± 0.37 mm overall, with no significant difference between males (1.98 ± 0.38 mm) and females (1.95 ± 0.35 mm) (p = 0.457). The anteroposterior, transverse, and corrected DRA diameters increased significantly with age (p < 0.05). The DRA diameter was significantly smaller than the proximal radial artery (PRA) diameter (1.97 ± 0.37 mm vs. 2.05 ± 0.33 mm, p < 0.001) but larger than the ulnar artery (UA) diameter (1.97 ± 0.37 mm vs. 1.88 ± 0.33 mm, p < 0.001). The proportions of patients with a DRA diameter greater than 2.0 mm and 1.5 mm were 38.83% and 86.89%, respectively. The proportions of patients with DRA diameters >2.0 mm and >1.5 mm increased significantly with age (p < 0.01). The percentages of individuals with a DRA/PRA ratio ≥1.0 were 55.10% overall, 52.12% in males, and 58.60% in females. DRA diameter showed significant correlations with age (r = 0.275, p < 0.01), height (r = 0.319, p < 0.01), weight (r = 0.319, p < 0.01), BMI (r = 0.241, p < 0.01), wrist circumference (r = 0.354, p < 0.01), PRA diameter (r = 0.521, p < 0.01), and UA diameter (r = 0.272, p < 0.01).

Conclusion

The DRA diameter in children increases with age and size, making cardiac catheterization is theoretically feasible. Preoperative evaluation of the vessel diameter and intraoperative ultrasound-guided intervention are recommended for paediatric catheterization via the DRA access.

Impact of sex differences on the feasibility and safety of distal radial access for coronary procedures: a multicenter prospective observational study

BACKGROUND

Conventional transradial access in women is associated with a lower success rate and a higher incidence of spasm compared to men. To date, the effect of sex on the performance of distal radial access (DRA) has not been fully elucidated. The aim of this study was to assess the impact of sex on catheterization success and other performance parameters of DRA procedures.

METHODS

This is a prospective three-center observational study. From August 2020 to September 2022, data from all consecutive patients who underwent DRA for coronary procedures were collected.

RESULTS

A total of 868 procedures were registered and stratified into two groups according to sex: women (n = 258) and men (n = 610). Female patients had less favorable baseline characteristics than male patients in terms of absent or weak pulse (29% vs. 17%; P  < 0.001), distal radial diameter (2.2 ± 0.3 vs. 2.4 ± 0.4 mm; P  < 0.001) and proximal radial diameter (2.5 ± 0.7 vs. 2.7 ± 0.7 mm; P  = 0.001). No differences in success rates were found in women compared to men (94.2% vs. 96.6%; P  = 0.135), with a higher presence of arterial spasm in women (5.8% vs. 3.0%; P  = 0.044). The preprocedural ultrasound evaluation was the only predictor of DRA success [odds ratio = 20.0 (4.739-83.333); P  < 0.001].

CONCLUSION

In patients undergoing coronary procedures, the success rate of DRA was high regardless of sex, with a higher incidence of arterial spasm in women.

Comparison of the Effect of a 6-French Glidesheath Slender and a Conventional Sheath on Distal Radial Artery Occlusion: A Randomized Controlled Trial

BACKGROUND

There is a lack of randomized clinical trials on whether the 6-French (Fr) Glidesheath Slender (GSS; Terumo, Tokyo, Japan) is superior to the 6-Fr conventional radial sheath (CS) with respect to the early-term incidence of distal radial artery occlusion (dRAO) in patients who have undergone coronary angiography (CAG) and/or percutaneous coronary intervention (PCI) via distal transradial access.

METHODS

This was a prospective, single-centre trial of patients who were randomized to undergo CAG and/or PCI with either a 6-Fr GSS or a 6-Fr CS. The primary end point was the incidence of dRAO at 24 hours postoperatively, evaluated using Doppler ultrasound.

RESULTS

A total of 620 patients were included in the study. The baseline patient and procedural characteristics were similar among the 2 groups. For the primary end point, the incidence of dRAO at 24 hours after the procedure was 1.0% (3/314) in the GSS group and 3.6% (11/306) in the CS group (risk ratio, 0.266; 95% confidence interval, 0.075-0.943; P = 0.027) according to the intention to treat analysis. For the secondary end points, the incidence of proximal radial artery occlusion was 0.3% (1/314) in the GSS group and 2.3% (7/306) in the CS group (P = 0.029). Other secondary end points, including the puncture success rate, procedural outcomes, other puncture-related outcomes, and access-related complications were not significantly different in the 2 groups.

CONCLUSIONS

The use of a thin-walled and hydrophilic coating sheath can reduce the incidence of early-term dRAO in patients who undergo CAG and/or PCI via the distal transradial access.

CLINICAL TRIAL REGISTRATION

NCT05501925.

Contemporary approach to cardiogenic shock care: a state-of-the-art review

Cardiogenic shock (CS) is a time-sensitive and hemodynamically complex syndrome with a broad spectrum of etiologies and clinical presentations. Despite contemporary therapies, CS continues to maintain high morbidity and mortality ranging from 35 to 50%. More recently, burgeoning observational research in this field aimed at enhancing the early recognition and characterization of the shock state through standardized team-based protocols, comprehensive hemodynamic profiling, and tailored and selective utilization of temporary mechanical circulatory support devices has been associated with improved outcomes. In this narrative review, we discuss the pathophysiology of CS, novel phenotypes, evolving definitions and staging systems, currently available pharmacologic and device-based therapies, standardized, team-based management protocols, and regionalized systems-of-care aimed at improving shock outcomes. We also explore opportunities for fertile investigation through randomized and non-randomized studies to address the prevailing knowledge gaps that will be critical to improving long-term outcomes.

A Randomized Comparison of Radial Artery Intimal Hyperplasia Following Distal Versus Proximal Transradial Access for Coronary Angiography: PRESERVE RADIAL

BACKGROUND

Distal transradial access (dTRA) is an alternative to conventional forearm transradial access (fTRA) for coronary angiography (CAG). Differences in healing of the radial artery (RA) in the forearm have not been evaluated between these 2 access strategies. We sought to compare the mean difference in forearm RA intimal-medial thickening (IMT) in patients randomized to dTRA versus fTRA.

METHODS AND RESULTS

In this single-center randomized clinical trial, 64 patients undergoing nonemergent CAG were randomized (1:1) to dTRA versus fTRA. Ultra-high-resolution (55-MHz) vascular ultrasound of the forearm and distal RA was performed pre-CAG and at 90 days. The primary end point was the mean change in forearm RA IMT. Secondary end points included procedural characteristics, vascular injury, RA occlusion, and ipsilateral hand pain and function. Baseline demographics and clinical characteristics, mean forearm RA IMT, and procedural specifics were similar between the dTRA and fTRA cohorts. There was no difference in mean change in forearm RA IMT between the 2 cohorts (0.07 versus 0.07 mm; P=0.37). No RA occlusions or signs of major vascular injury were observed at 90 days. Ipsilateral hand pain and function (Borg pain scale score: 12 versus 11; P=0.24; Disabilities of the Arm, Shoulders, and Hand scale score: 6 versus 8; P=0.46) were comparable.

CONCLUSIONS

Following CAG, dTRA was associated with no differences in mean change of forearm RA IMT, hand pain, and function versus fTRA for CAG. Further investigation is warranted to elucidate mechanisms and predictors of RA healing and identify effective strategies to preserving RA integrity for repeated procedures.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04801901.

Distal Radial Access for Coronary Procedures in a Large Prospective Multicenter Registry: The KODRA Trial

BACKGROUND

Distal radial access (DRA) as an alternative access route lacks evidence, despite its recent reputation.

OBJECTIVES

The aim of this study was to evaluate the safety and feasibility of DRA on the basis of daily practice.

METHODS

The KODRA (Korean Prospective Registry for Evaluating the Safety and Efficacy of Distal Radial Approach) trial was a prospective multicenter registry conducted at 14 hospitals between September 2019 and September 2021. The primary endpoints were the success rates of coronary angiography (CAG) and percutaneous coronary intervention (PCI). The secondary endpoints included successful distal radial artery puncture, access-site crossover, access site-related complications, bleeding events, and predictors of puncture failure.

RESULTS

A total of 4,977 among 5,712 screened patients were recruited after the exclusion of 735 patients. The primary endpoints, the success rates of CAG and PCI via DRA, were 100% and 98.8%, respectively, among successful punctures of the distal radial artery (94.4%). Access-site crossover occurred in 333 patients (6.7%). The rates of distal radial artery occlusion and radial artery occlusion by palpation were 0.8% (36 of 4,340) and 0.8% (33 of 4,340) at 1-month follow-up. DRA-related bleeding events were observed in 3.3% of patients, without serious hematoma. Multilevel logistic regression analysis identified weak pulse (OR: 9.994; 95% CI: 7.252-13.774) and DRA experience <100 cases (OR: 2.187; 95% CI: 1.383-3.456) as predictors of puncture failure.

CONCLUSIONS

In this large-scale prospective multicenter registry, DRA demonstrated high success rates of CAG and PCI, with a high rate of puncture success but low rates of distal radial artery occlusion, radial artery occlusion, bleeding events, and procedure-related complications. Weak pulse and DRA experience <100 cases were predictors of puncture failure. (Korean Prospective Registry for Evaluating the Safety and Efficacy of Distal Radial Approach [KODRA]; NCT04080700).

Randomized comparison of Glidesheath Slender with conventional 5Fr arterial sheaths for coronary angiography through the distal radial artery

BACKGROUND

The potential benefits of the thin-walled 5F Glidesheath Slender sheath in the distal transradial access (dTRA) have not been investigated. This study aimed to compare the Glidesheath Slender versus conventional 5Fr arterial sheaths in patients undergoing diagnostic coronary angiography (CAG) through the dTRA.

METHODS

A total of 352 consecutive patients with an indication for CAG were randomized (1:1) to Glidesheath Slender 5Fr versus a conventional 5Fr arterial sheath for dTRA. The primary endpoint was the rate of successful hemostasis at 30 minutes after sheath removal. Follow-up ultrasound of the right radial and distal radial artery was performed 7-10 days after the procedure.

RESULTS

After exclusion of patients where a 6Fr sheath or crossover of access site was required, 108 patients in the Glidesheath Slender and 105 patients in the conventional 5Fr arterial sheath group were included in the analysis. The crossover rate to conventional radial access and the rate of successful hemostasis at 30 minutes after sheath removal were similar between the two groups (18.9% in the Glidesheath slender vs. 22% in the control group; P=0.460, and 62% vs. 51.4%; P=0.118, respectively). The level of pain associated with the procedure was significantly lower in the Glidesheath Slender group (2.69 vs. 3.29 in the control group; P=0.02). No significant difference was recorded between the two groups in the rate of access-related complications.

CONCLUSIONS

Use of Glidesheath Slender for dTRA did not increase the rate of early hemostasis compared with conventional arterial sheath.

Prospective evaluation of efficacy and safety of distal radial and radial artery access using a novel articulating-tip guidewire

BACKGROUND

Guidewire-facilitated access to peripheral vessels is commonplace in vascular access, but guidewire insertion into small vessels, such as the radial and distal radial arteries, can still be challenging. Failure to gain access on the first attempt may contribute to increased risks of procedural complications, such as vessel dissection, spasm, and occlusion. This research assessed the safety and efficacy of radial and distal radial artery access using a novel, FDA-cleared, small-core-diameter guidewire with an articulating tip, under ultrasound guidance.

METHODS

This was a prospective, single-arm, single-center trial. Patients in need of vascular access were screened for participation and enrolled in the study. Guidewire insertion was attempted by four physicians (three interventional radiologists and an interventional nephrologist) at 162 arterial sites-65 radial and 97 distal radial, having a mean diameter of 2.0 mm.

RESULTS

First-attempt successful placement of the guidewire in the artery occurred at 87.6% of access sites (142/162) and differences in the success rate between the radial and distal radial arteries or between vessels with diameter smaller or larger than 2 mm were not observed (62/68 and 67/77, respectively; p = 0.6). Four of the five reported adverse events were unrelated to the study device or procedure. Two of the three distal radial artery spasms occurred before the guidewire was used. The other two events were a radial artery spasm, and a distal radial artery site hematoma. All adverse events resolved spontaneously.

CONCLUSIONS

First-attempt placement of a novel articulating tip guidewire in the radial and distal radial arteries occurred at a high rate in our study and was not associated with safety concerns.

Distal radial access for neuroangiography and neurointerventions: systematic review and meta-analysis

BACKGROUND

Many studies have shown that coronary angiography (CAG) and percutaneous coronary intervention (PCI) via distal radial access (DRA) are safe and effective. Safety and efficacy of neuroangiography and neurointerventions via DRA are unknown.

PURPOSE

Search the literatures on neuroangiography and neurointerventions via DRA and conduct a systematic review and meta-analysis.

METHODS

PubMed, Embase and Cochrane were searched from inception to November 10, 2022. After literature screening, data extraction and assessment of literature quality, random effects model was used for meta-analysis.

RESULTS

A total of 236 literatures were retrieved, and 17 literatures including 1163 patients were finally included for meta-analysis.The pooled access success rate was 0.96 (95% confidence interval, 0.94-0.98), and the heterogeneity was obvious (I2 = 55.5%). The pooled access-related complications incidence rate was 0.03 (95% confidence interval, 0.02-0.05), and the heterogeneity was not obvious (I2 = 15.8%).

CONCLUSION

Neuroangiography and neurointerventions via DRA may be safe and effective. DRA is an alternative access for neuroangiography and neurointerventions.

Distal Versus Proximal Radial Artery Access for Cardiac Catheterization: 30-Day Outcomes of the DIPRA Study

Background Proximal radial artery (pRA) access for cardiac catheterization is safe but can jeopardize subsequent use of the artery because of occlusion. Distal radial artery (dRA) access in the anatomical snuffbox preserves the radial artery, but safety and potential detrimental effects on hand function are unknown. Methods and Results In the DIPRA (Distal Versus Proximal Radial Artery Access for Cardiac Catheterization and Intervention) study, a single-center trial, 300 patients were randomized 1:1 to cardiac catheterization through dRA or pRA. The primary end point of change in hand function from baseline to 30 days was a composite of the QuickDASH (Quick Disabilities of the Arm, Shoulder and Hand) questionnaire, hand-grip test, and thumb forefinger pinch test. Secondary end points included access feasibility and complications; 254 of 300 patients completed follow-up at 30 days; of these, 128 were randomized to dRA and 126 to pRA with balanced demographic and procedural characteristics. Both groups had similar rates of access site bleeding (dRA 0% versus pRA 1.4%; P=0.25). Six patients with dRA failed access compared with 2 patients with pRA. Radial artery occlusion occurred in 2 pRA versus none in dRA. There were no significant differences in change in hand function, median hand-grip (dRA 0 [-3.2, 3.3] versus pRA 0.7 [-2.3, 3.3] kg; P=0.21), pinch-grip (dRA -0.3 [-1.2, 0.5] versus pRA 0 [-0.9, 0.9] kg; P=0.09), and QuickDASH (dRA 0 [-4.6, 2.3] versus pRA 0 [-4.6, 2.3] points, P=0.96). There was no significant difference in the composite of hand function between pRA and dRA. Conclusions dRA is a safe strategy for cardiac catheterization with a low complication rate. Compared with pRA, there is no increased risk of hand dysfunction at 30 days. Registration URL: https://www.ClinicalTrials.gov. Unique identifier: NCT04318990.

Distal versus conventional transradial access for diagnostic cerebral angiography and neurointerventional procedures: A systematic review and meta-analysis

BACKGROUND

Distal transradial artery access (dTRA) has received increasing consideration for performing diagnostic cerebral angiography and neurointerventional procedures. In this meta-analysis, we aim to evaluate the safety and efficacy of dTRA compared to conventional transradial access (cTRA) for cerebral angiography and neurointerventions.

METHOD

A systematic review and meta-analysis were conducted on studies investigating outcomes of dTRA and cTRA in neurointerventions. The primary outcome was technical success rates. Secondary outcomes included access site complication rates, crossover rates to alternative vessels, fluoroscopy time, and contrast volume. The random effects model was used to calculate the mean difference (MD) and odds ratios (OR) with 95% confidence intervals (Cl).

RESULTS

Eight retrospective observational studies with a total of 1477 patients who underwent 1175 diagnostic cerebral angiography and 516 neurointerventional procedures using 546 dTRA and 1164 cTRA approaches were included in our meta-analysis. The technical success rate was similar between dTRA and cTRA groups (95.8% vs 91.4%; OR:1.65; 95% Cl: 0.52 to 5.22; P = 0.40). Similarly, no difference was seen in dTRA and cTRA regarding access site complications (2% vs 1.4%; OR: 1.31; 95% CI: 0.47 to 3.61; P = 0.61) and access site crossover (2.1% vs 5.3%; OR: 0.55; 95% Cl: 0.28 to 1.05; P = 0.07). After resolving heterogeneity among included studies, dTRA was associated with a shorter fluoroscopy time (MD: -0.91 min; 95% CI: -1.74 to -0.09; P = 0.03) and lower contrast volume (MD: -8.32 mL; 95% CI = -14.7 to -1.94; P = 0.011).

CONCLUSION

Our findings suggest that the dTRA approach is a safe and effective alternative to the cTRA approach in patients undergoing cerebral angiography and neurointerventions.

Transradial versus transfemoral access for posterior circulation endovascular intervention: A systematic review and meta-analysis

OBJECTIVE

Transradial access (TRA) provides a more direct entry to posterior circulation system for endovascular therapy compared to transfemoral access (TFA). This meta-analysis aims to evaluate the safety and feasibility of TRA in neurointervention of posterior circulation.

MATERIALS AND METHODS

A systematic search was conducted in the Wanfang Data, CBM, PubMed, Embase, Cochrane Library, Web of Science databases. The primary outcomes included total complications and access site complications. Secondary outcomes were single puncture success, procedural success, access cross-over, catheter retention time and fluoroscopy time.

RESULTS

Six studies encompassing 297 patients were included in the meta-analysis. Compared to the TFA group, the TRA group showed significantly decreased total complications (odds ratio [OR] = 0.29, 95% confidence interval [CI] [0.12, 0.73], p < 0.01) and access site complications (OR = 0.19, 95%CI [0.06, 0.62], p < 0.01), yet it had a longer catheter retention time (mean difference [MD] = 0.80, 95%CI [0.60, 1.00], p < 0.01). There were no significant differences in single puncture success (OR = 3.68, 95%CI[0.38, 35.86], p = 0.26), procedural success (OR = 0.30，95%CI [0.05, 1.73], p = 0.18), access cross-over (OR = 2.29, 95%CI [0.19, 28.26], p = 0.52), fluoroscopy time (MD = 0.97, 95%CI [- 0.91, 2.84], p = 0.31) between the TRA and TFA groups.

CONCLUSION

This meta-analysis demonstrated that TRA is a safe and feasible alternative to TFA for neurointervention in the posterior circulation. TRA showed significantly decreased total complications and access site complications, yet it had a longer catheter retention time than TFA.

Distal Radial Approach in Coronary Angiography Using a Transdermal Nitroglycerin Patch: Double-Blinded Randomized Trial

Nitroglycerin dilates the radial artery and prevents spasm, which increases the success rate of sheath cannulation through the conventional transradial approach. However, the effects of nitroglycerin on distal radial approach (DRA) procedures are not known. The aim of this study is to elucidate whether a transdermal nitroglycerin patch improves the rate of successful DRA cannulation. A total of 92 patients scheduled for coronary angiography by means of DRA randomly received (1:1) a transdermal nitroglycerin patch preintegrated with the covering material or only the covering material on their upper arm on the side of the puncture. The diameter of the distal radial artery was evaluated with ultrasound at baseline and after application. DRA procedures were performed in a double-blind fashion. The primary outcome was the rate of successful palpation-guided distal radial artery cannulation with the first puncture. The nitroglycerin group had larger distal radial artery diameter after patch application than that of the no-treatment group (mean, 3.21 mm vs 2.71 mm, p <0.001), but not at baseline (mean, 2.64 mm vs 2.64 mm, p = 0.965).The nitroglycerin group had a significantly higher success rate of DRA cannulation with the first puncture than that of the no-treatment group (59% vs 24%, p = 0.001; odds ratio 4.5, 95% confidence interval 1.9 to 11.0). The nitroglycerin group required fewer punctures than did the no-treatment group (median, 1 vs 3, p = 0.019). There were no significant differences in the occurrence of hypotension between the 2 groups. No patients experienced radial artery occlusion. In conclusion, transdermal nitroglycerin patch application safely facilitates DRA cannulation. Trial Registration: Japan Registry of Clinical Trials, https://jrct.niph.go.jp/ (identifier: jRCTs051210128).

Comparison Between Distal Trans-radial Access and Conventional Trans-radial Access for Coronary Angiography

Background Compared with a conventional wrist puncture for radial artery catheterization, a distal radial artery puncture has the advantage of reducing the incidence of radial artery occlusion (RAO). Aim The present study was designed to evaluate the feasibility of distal trans-radial access compared with conventional trans-radial access for coronary angiography. Methods A prospective, randomized, single-blinded, comparative study was conducted at a tertiary care center in India between December 2018 and November 2020. A total of 420 patients (aged >18 years) with signs and symptoms suggestive of coronary artery disease (CAD) and with a palpable radial artery in anatomical snuffbox were randomized into two groups. Group A comprised patients accessed at the distal trans-radial site, and Group B consisted of patients accessed at the conventional trans-radial site for coronary angiography. Baseline demographics, clinical history, and risk factors for CAD were documented. Procedural-related parameters and complications were compared between the two groups. Results The procedural success rate was non-significant between Group A and Group B (96% vs. 98%; p=0.38). Puncture in a single attempt was higher in Group B compared to Group A (92% vs. 78%; p<0.001). There was no significant difference between Group A and Group B for operation time (p=0.207), fluoroscopy time (p=0.183), and contrast volume (p=0.345). The rate of RAO was higher in Group B compared to Group A (13% vs. 2%; p<0.001). Radial artery hematoma/swelling at the puncture site between Group A (10%) and Group B (8%) was not significant (p=0.61). Post-procedural hemostasis time in Group A was 28 ± 7.86 minutes, and in Group B was 24 ± 6.23 minutes. Both post-procedural persistence of pain (p<0.001) and hand clumsiness (p<0.001) were significantly higher in Group B compared to Group A. Conclusion For coronary angiography, the distal trans-radial access site is a reliable and secure alternate access site.

Risk factors for radial artery occlusion after neurointervention for unruptured intracranial aneurysm via transradial access

PURPOSE

Neurointervention via transradial access (TRA) is less invasive than via transfemoral access. However, radial artery occlusion (RAO) may occur with TRA. The purpose of this study was to explore risk factors for RAO after coil embolization of unruptured intracranial aneurysms (UIAs) via TRA.

METHODS

Forty-two consecutive patients who underwent coil embolization for UIAs via TRA between March 2021 and March 2022 and were available for angiographic evaluation 1 year after treatment were retrospectively reviewed. Multivariate logistic regression analysis was conducted to identify potential risk factors for RAO.

RESULTS

Seventeen (40%) of the 42 patients showed RAO. Compared with the non-RAO group, radial artery size was significantly smaller (2.2 mm [interquartile range (IQR): 2.1, 2.4 mm] vs 2.6 mm [IQR: 2.5, 2.7 mm]; p = 0.001) and the incidence of radial artery spasm (RAS) was significantly higher in the RAO group. Multivariate analysis identified radial artery size (odds ratio [OR] 4.9 × 10^-3, 95% confidence interval [CI] 6.4 × 10^-5-0.38) and incidence of RAS (OR 14.8, 95%CI 2.1-105) as significant independent predictors of subsequent RAO. Based on receiver operating characteristic (ROC) curve analysis, the optimal cutoff for radial artery size was 2.5 mm (sensitivity, 82.4%; specificity, 76.0%; area under the ROC curve, 0.80 [95%CI 0.66-0.95]).

CONCLUSION

Radial artery size and RAS represent reliable parameters for predicting RAO 1 year after coil embolization for UIA via TRA. Prophylaxis against RAS and limiting neurointervention via TRA to patients with radial artery larger than 2.5 mm in diameter may reduce the risk of postoperative RAO.

A Randomized Comparison of Radial Artery Intimal Hyperplasia Following Distal vs. Proximal Transradial Access for Coronary Angiography: PRESERVE RADIAL Trial

Background

Distal transradial access (dTRA) is an alternative to conventional forearm transradial access (fTRA) for coronary angiography (CAG). Differences in healing of the radial artery in the forearm (FRA) have not been evaluated between these 2 access strategies. We sought to compare FRA intimal-medial thickening (IMT) in patients randomized to dTRA vs. fTRA for CAG.

Methods and Results

Sixty-four consecutive patients undergoing non-emergent CAG were randomized (1:1) to dTRA vs. fTRA. Ultrahigh resolution (55 MHz) vascular ultrasound) of the FRA and distal RA was performed pre-CAG and at 90 days. Primary endpoint was 90-day FRA IMT. Secondary endpoints included procedural characteristics, vascular injury, RA occlusion and ipsilateral hand pain and function. Baseline demographics and clinical characteristics, mean FRA IMT, time to RA access, procedure time, and radiation exposure were similar between the dTRA and fTRA cohorts. There were no between group differences in 90-day FRA IMT (0.37 mm vs 0.38 mm, respectively; p =0.73). No RA occlusions or signs of major vascular injury were observed at 90 days. Ipsilateral hand pain and function (Borg pain scale:12 vs 11, p =0.24; DASH scores: 6 vs 8, p =0.46) were comparable.

Conclusions

In this single center randomized clinical trial, similar patterns of FRA vascular healing at 90 days, procedural results as well as hand pain and function were observed following dTRA vs. fTRA for CAG. Further investigation is warranted to better understand the mechanistics and predictors of RA healing and to identify strategies aimed at preserving RA integrity for future procedures.

What is New?

DTRA has been proposed as an alternative to traditional fTRA in the wrist for CAG and PCI because of ergonomic and post-procedural recovery benefits to the patient, as well as potential reductions in occlusion of the FRA.There are gaps in knowledge, however, regarding potential differences in remodeling of the FRA in patients undergoing dTRA versus fTRA.In this randomized clinical trial, there were no differences in IMT and patterns of vascular injury and healing, using ultrahigh resolution (55 MHz) ultrasound, at 90 days in patients randomized to dTRA or FTRA for elective and non-emergent CAG and PCI.

What Are the Clinical Implications

Our findings highlight the need for further inquiry through large multicenter randomized clinical trials to better the understand the mechanistics and predictors of IMT and to identify strategies to mitigate the adverse effects of vessel remodeling in patients undergoing TRA across the entire severity spectrum of cardiovascular disease.

Comparison of the feasibility and safety between distal transradial access and conventional transradial access in patients with acute chest pain: a single-center cohort study using propensity score matching

BACKGROUND

Distal transradial access (dTRA) has been suggested to have great advantages over cTRA. However, there is a lack of preliminary data on dTRA in patients undergoing emergency coronary angiography (CAG) or percutaneous coronary intervention (PCI). To explore the feasibility and safety of distal transradial access in patients with acute chest pain.

METHODS

A total of 1269 patients complaining of acute chest pain in our emergency department from January 2020 to February 2022 were retrospectively included. The patients who met the inclusion criteria were divided into the conventional transradial access (cTRA) group (n = 238) and the dTRA group (n = 158). Propensity score matching was used to minimize the baseline differences.

RESULTS

The cannulation success rate in the dTRA group was significantly lower than that in the cTRA group (87.41% vs. 94.81%, p < 0.05). No significant differences in the puncture time and total procedure time were noted between the two groups (p > 0.05). Compared with the cTRA group, the hemostasis duration was significantly shorter [4(4, 4) h vs. 10(8, 10) h, p < 0.001) and the incidence of minor bleeding (BARC Type I and II) was significantly lower in the dTRA group than that in the cTRA group (0.85% vs. 5.48%, p = 0.045). Asymptomatic radial artery occlusion was observed in six patients (5.83%) in the cTRA group and one patient (1.14%) in the dTRA group (p = 0.126). The subgroup analysis of ST-elevation myocardial infarction (STEMI) showed no significant differences in the puncture time, D-to-B time or total procedure time between the two groups.

CONCLUSIONS

The dTRA for emergency CAG or PCI has an acceptable success rate and puncture time, a shorter hemostasis time, and a downward trend in RAO rate compared to the cTRA. The dTRA did not increase the D-to-B time in emergency coronary interventions in STEMI patients. On the contrary, a low incidence of RAO by the dTRA created an opportunity for future coronary interventions in non-culprit vessels in the same access.

TRIAL REGISTRATION

Retrospectively registered in Chinese Clinical Trial Registry (registry number: ChiCTR2200061104, date of registration: June 15, 2022).

Procedural embolic protection strategies for carotid artery stenting: current status and future prospects

INTRODUCTION

Carotid artery angioplasty and stenting (CAS) is an established procedure to treat carotid artery stenosis for either primary or secondary prevention of stroke. Randomized clinical trials have shown an increased risk of periprocedural cerebrovascular events with CAS compared with carotid endarterectomy (CEA). Several strategies have been proposed to mitigate this risk, including alternative vascular access site, proximal/distal embolic protection devices, and dual-layer stents, among others.

AREAS COVERED

This review provides a general overview of current embolic protection strategies for CAS. The phases of the procedure which can affect the early risk of stroke and how to reduce it with novel techniques and devices have been discussed.

EXPERT OPINION

Innovations in device technologies have dramatically improved the safety and efficacy of CAS. To minimize the gap with surgery, a thorough, patient-oriented approach should be pursued. Endovascular technologies and techniques should be selected on an individual basis to address unique lesion characteristics and vascular anatomies. Meticulous pre-procedural planning, both clinical and anatomical, is needed to assess the embolic risk of each procedure. Only by having an in-depth understanding of the wide range of available endovascular devices and techniques, the operator will choose the most appropriate strategy to optimize CAS results.